Centrifugal governor



Feb. 6 GARDNER 2,368,822

' CENTRIFUGAL GOVERNOR Filed July 2, 1943 fllq Gardner force causes theweight 25 to Patented Feb. 6, 1945 7 2,368,822 CENTRIFUGAL GOVERNOR DaleGardner, Detroit, Mich., M. Holley and Earl assignor to George HolleyApplication July 2, 1943, Serial No. 493,304

6 Claims.

The object of this invention is to control the speed of an internalcombustion engine.

Fig. 1 shows diagrammatically the elements of my invention.

Fig. 2 shows the range of speeds between which the governor can beadjusted to function.

In Fig. 1, I is the air entrance, I is the venturi into which dischargesa fuel nozzle I2. I3 is a mixture outlet in which is located a throttlevalve I4 controlled by the throttle lever 3| which is automaticallycontrolled by the governor rod I5 and manually controlled by a rod I!which engages with the lever 3| so as to close the throttle I4. Thethrottle is opened by the spring I6 and is closed automatically by thegovernor rod I5 and manually by the rod I I.

The right-hand side of diaphragm I8 is subjected to the suction in themixture outlet I3 through the restricted opening 32 so as to close thethrottle when the speed becomes excessive. This suction in the mixtureoutlet I3 is conducted to a chamber I 9 located to the right-hand sideof the diaphragm I8 thru the restricted opening 32, passage 20, past anadjustable needle 2| which is located in a passage 24 between thepassage and the chamber l9.

Atmospheric air is admitted to the chamber l9 through an opening 22which is formed in the wall of a chamber 23 rotated by a shaft 28. Thischamber is connected to the chamber I9 through a passage 24 anda'restriction 33. A centrifugal weight 25 is slidably mountedinside therotating chamber 23 which is rotated at engine speed or at some speedproportional to engine speed. A spring 26 pulls the weight 25 off itsseat so that the opening 22 is always slightly open. A taperedprojection 21 on the end of the weight 25 forms a variable resistance tothe flow of atmospheric air through the opening 22 into the chamber I9.

This chamber 23 and its shaft 28 driven by the engine at engine speed orsome fraction thereof 4 takes the place of the centrifugal weights inany ordinary mechanical governor.

A relatively large passage 29 free from restric tions connects theventuri II with the passage 20 so that when the throttle I3 is wide openand there is little or no suction in the mixture outlet I3 the devicecan then operate with the Venturi suction. With the throttle wide open,the suction in the venturi II is transmitted through the passage 29 pasta check valve 30 and a needle valve 2 I. The governor functions whenevercentrifugal close the opening 22 when the suction in the throat of theventuri II is powerful enough to overcome the pull of the turi suction.

spring I6. Thereupon the throttle closes and then the suction in "theventuri II falls and the suction in the mixture outlet I3 increases. Thecheck valve 30 is provided so that when the throttle I3 begins to close,the check valve closes automatically. Thereafter the suction in themixture outlet I3 is able to furnish the operating means so that thegovernor can function without interference from the suction or ratherlack of suction in the venturi II as the suction in the mixture outletis great compared with the Ven- For this reason a restriction is placedin the exit from the passage 20 and is made small compared with passage29.

The position of the tapered portion 21 of the centrifugal weight 25 inthe atmospheric opening 22 determines the amount of suction in thechamber I9, and therefore determines the position of the throttle I4.Obviously throttle I4 must close until equilibrium is established sothat the speed of the engine is such as to restrict the atmosphericopening 22 so that the restricted opening 2| subjects the chamber I9 tohold the throttle [4 in the position shown as determined by the pull ofthe spring I6. The restriction 32 is smaller than the opening past thecheck valve 30 so that at wide open throttle the diaphragm I8 respondsto the suction in the venturi II.

In Fig. 2 the line AB represents the normal increase in power withincrease in speed. At the point B with the adjustment 2| opened upfairly wide the power falls off along the line BC and at 2700 R. P. M.the throttle is completely closed, the point C (2700) being the point ofidle cutoff. Now, let us assume that the point B is 49 hp. at 2400 R. P.M. and let us also assume that the adjustment 2| is rotated so as torestrict the passage past the adjustment 2|. The speed now increases to2500 before there is sufi'icient vacuum in the venturi I0 to cause thediaphragm 8 to move the throttle I4 towards the closed position. Thecentrifugal weight 25 then moves rapidly to close the opening 22 and thepower falls steeply along the line DC. With this adjustment the hp. hasrisen at the point D to say 53 hp. Therefore, there has been a gain inpower of 4 hp. or 8% due to the restriction at the needle valve 2|.However, this can be carried too far, and if the line DC becomes toosteep there is a tendency for the engine to hunt and for the R. P. M. ofthe engine to alternately increase and to decrease in a steady rhythm.If this happens, the needle valve 2| is opened up to avoid any suchhunting.

What I claim is:

1. In an internal combustion engine having a carburetor whichincorporates a venturi acting as the main air passage to said engine, athrottle valve controlling the air flow thru said venturi to the engineinlet passage, a governor comprising a. rotating chamber, a weighttherein, yielda'ble means engaging with said weight so as to oppose theaction of the centrifugal force imparted to said weight, an atmosphericopening leading into said chamber, a variable restriction adapted to bemoved by said centrifugal weight so as to decrease the area of saidOpening as the speed increases, a moving wall, a stationary chamberassociated therewith, a passage connecting said rotating chamber withsaid chamber, a connection from said moving wall to said throttle,spring means adapted to open said throttle so as to oppose the movementof said moving wall when the stationary chamber is subjected to suction,a by-pass connecting the engine inlet passage with the throat of saidventuri, a non-return check valve in said by-pass near the point whereit connects with the venturi, said check valve being adapted to openonly when the vacuum in the venturi exceeds the depression in the engineinlet passage, a passage leading out of said by-pass between said checkvalve and said engine inlet and into said chamber to subject saidchamber to the suction created by the air entering said engine on bothsides of said throttle.

2. A device as set forth in claim 1 in which there is an adjustablerestriction in the last mentioned passage between said by-pass and saidchamber.

3. A device as set forth in claim 1 in which there is a restriction insaid by-pass adjacent to the point where it connects with the engineinlet passage.

4. In an internal combustion engine having a carburetor whichincorporates a venturi acting as the main air passage to said engine, athrottle valve controlling the flow thru said venturi, a centrifugalgovernor adapted to be driven by said engine, a speed regulating valveoperated by said governor, an orifice open to the atmosphere and adaptedto be controlled by said regulating valve, a passage connecting saidorifice to the throat of said venturi, a non-return check valve thereinlocated adjacent to said venturi, a second passage connected to saidfirst mentioned passage between said check valve and said regulatingvalve and leading to the main air passage on the engine side of saidthrottle valve, a chamber connected to the first-mentioned passagebetween said check valve and said regulating 'valve, a moving wall insaid chamber, a connection from said moving wall to said throttle,adapted to close said throttle in response to suction in said chamber,yielding means tending to open said throttle valve, manually operatedmeans for closing said throttle valve.

5. A device as set forth in claim 4 in which there is a restriction insaid second passage adjacent to the point where it connects with theengine inlet passage.

6. A device as set forth in claim 4 in which there is an adjustablerestriction in the first passage between the point where it connectswith said chamber and said check valve.

DALE GARDNER.

